An instrument panel is installed upon a frontal portion of an interior of a passenger compartment within a vehicle, such as an automobile. A steering support member, which extends in approximately a direction of a width of the vehicle, and which is capable of connecting left and right panels of the vehicle, is positioned within the instrument panel. Front and back column brackets are attached upon a lower portion of the steering support member. A steering column, which extends in approximately a forward and backward direction of the vehicle and is positioned upon a lower portion of the steering support member, is thus anchored at front and back two locations thereof to front and back fastening points that are provided on the front and back column brackets, respectively, in a suspension support state.
Here, such a steering support member 1 is normally configured of a metallic cylindrical pipe 2, such as is depicted in FIG. 7. Whereas the column brackets 3 and 4 may comprise both an integrated configuration and a separated configuration, the column brackets 3 and 4 comprise the integrated configuration in the present circumstance. The steering support member 1 is fitted with a cylindrical receptacle surface that is formed by the integrated column brackets 3 and 4, and is further fixed in place thereupon by a weld portion 5. The weld portion 5 is provided along the cylindrical receptacle surface.
In the circumstance wherein the steering support member 1 is structured by the metallic cylindrical pipe 2, however, the configuration thereof is structurally weakened with respect to a twisting motion 6, thereby giving rise to a trend wherein a rigidity with respect to a vertical oscillation of the steering column may prove insufficient as a result, and a problem thus results in that a necessity arises for increasing a diameter or a thickness of the cylindrical pipe 2 as a countermeasure against the insufficient rigidity thereof.
As a consequence thereof, a proposal has been put forth for such as forming the steering support member 1 into a variant cross-section other than a cross-section of the cylindrical pipe 2, i.e., other than a circular cross-section; refer, as an instance thereof, to Japanese Patent Application Laid Open No. S63-49587 for particulars.
As an instance thereof, the steering support member 1 is configured to include a rectangular pipe 11 having a square cross-section wherein each of surfaces 7 to 10 of the steering support member faces front and back, up and down, respectively, as is depicted in FIG. 8.